1. Field of the Invention
The invention relates to an apparatus for skinning fish fillets, comprising a skin entraining roller driven to rotate, a presser shoe having a presser face opposing the circumferential surface of the skin entraining roller and leaving a gap with respect to the roller, and a skinning knife driven to oscillate, which, with its cutting edge opposes the circumferential surface of the skin entraining roller at a distance thereto.
2. Prior Art
Such skinning apparatus is e.g. known from German Patent 37 00 324. In this known apparatus, the skinning knife is guided in a slot of the presser shoe, the position of the cutting edge being defined, relative to the blunt edge of the pressure shoe, by guiding elements in the shape of feather keys, said blunt edge confining the entrance side of the presser face. The guiding elements engage corresponding recesses in the skinning knife and ensure that the cutting edge lies slightly upstream or ahead of said pressure shoe edge.
This apparatus, which has been especially designed for the skinning of fillets of flatfish, has brought about excellent results and proved extremely reliable, because the rather intimate and strong connection of the skin with the muscle flesh which is characteristic for this species of fish and is caused by fine tendons, can be severed without problems.
However, with regard to the yield in fillet meat to be obtained with this apparatus, certain disadvantages occur in the application of this design. Such drawbacks already become apparent optically in that the so-called "silver mirror", which is a quality characteristic of skinned fillets, is missing on the skin side of the fillets. The reason for this is that this skinning procedure depends on the severing of a layer of uniform thickness including the skin, which thickness can be predetermined by setting or adjustment. By such processing it cannot be avoided that, in regions in which the skin is thinner than in other regions, a layer of meat and thus the silver mirror are severed as well.
Although it is known that the silver mirror can be maintained in the case of fillets of flatfish when using a fixedly arranged knife having a defined sharpness, no constant and reliable operation can be carried out therewith. Finally, there is a further drawback in that the tail area splits along the line of the backbone so that the skinned fillet assumes a dovetail-shaped appearance which is considered to be a quality impairment.
3. Object of the Invention
It is the main object of the present invention to remove the drawbacks of the prior art apparatus.
It is a particular object to suggest an apparatus by means of which it becomes possible to skin flatfish fillets while maintaining their silver mirror.
It is yet another important object of the invention to suggest an apparatus which safeguards that a splitting of the tail area is avoided.